Do or die for Steelers and Ravens

The Pittsburgh Steelers quarterback Ben Roethlisberger will face the Baltimore Ravens' formidable defence today.

In the NFL, Week 11 is known as Separation Sunday and one of today's pivotal encounters pits a concussion-prone quarterback against a defence who regard him as a prime target for the brain-rattling mayhem that has made them feared throughout the NFL. Little will be settled today, but the foundation will be laid for who separate themselves from the pack, continue to cling to its edges or fall off the ledge completely.

The defending Super Bowl champion Pittsburgh Steelers (6-4) hope to stop a two-game losing run when they meet the Baltimore Ravens (5-5), their AFC North rivals, in a key game for both. The Steelers and the Ravens both trail the division-leading Cincinnati Bengals and cannot afford another setback if they are to prolong their season into January. The Steelers will be working under a cloud as their quarterback Ben Roethlisberger tries to play a week after sustaining his second concussion in a year. In 2006, Roethlisberger played the worst game of his career a week after suffering a concussion, throwing four interceptions, two of which were returned for touchdowns. After passing a battery of tests, Roethlisberger says he is fit but will be closely monitored against the destructive Ravens, who sacked him 10 times last season.

"This is a violent sport we play," said Roethlisberger. Especially the way the Ravens play. Baltimore's reputation is well known and well respected. "Everybody wants to hit the quarterback," the Steelers' tackle Max Starks said of the Ravens' approach. The same is true of the Steelers, who have had great success against Baltimore's Joe Flacco. Flacco has not led the Ravens to a touchdown in two games and completed only 44.9 per cent of his passes with five interceptions in the three games between them last year. The quarterback who manages to be more effective will decide the game.

Worth noting: if Roethlisberger is pulled his replacement will be Dennis Dixon, a rookie who has thrown only one NFL pass. The Houston Texans (5-5) are facing their last chance to make the play-offs for the first time when they host the undefeated Indianapolis Colts (10-0). Houston are 1-14 against the Colts since coming into the league and have lost back-to-back home games by three points each. That contrasts with the Colts' 19-game regular-season winning streak, the second longest in NFL history.

But Indianapolis have won their last four by a total of 10 points and could be ripe for an upset. Both have struggled to run the ball but have top-flight quarterbacks in Peyton Manning and Matt Schaub. Manning has already thrown for more than 3,000 yards this season. Schaub needs less than 50 yards to join him. The Chicago Bears (4-6) face the Minnesota Vikings (9-1) having lost five of their last six. Quarterback Jay Cutler, who was acquired to make them a contender, leads the league in interceptions with 18. Nothing he can do will counter Minnesota's defence, which is stingy against the run and leads the NFL in sacks, or a Minnesota offence led by 40-year-old Brett Favre, who is having a superb year.

The Carolina Panthers (4-6) were 12-4 a year ago. Today they're on life support and must beat the New York Jets (4-6) to keep any play-off hopes alive. Quarterback Jake Delhomme never seemed to recover from an abysmal play-off performance last year and Carolina's injury-riddled defence is slumping, although facing the Jets' rookie quarterback Mark Sanchez may help. Sanchez committed five turnovers last weekend and is barely completing 50 per cent of his passes.

The Washington Redskins (3-7) cannot make the play-offs but could make it hard on the Philadelphia Eagles (6-4), who must win to keep pace in the NFC North. Washington have lost five of their last six and all five road games. This should be No 6. The Arizona Cardinals (7-3) will try to cool off the Tennessee Titans (4-6), who have won four in a row since quarterback Vince Young replaced Kerry Collins.

Young is 22-11 as a starter in his career not because he is a great passer but because he is a dangerous runner. Young's legs have opened up room for running back Chris Johnson, who has five straight 100-yard games. The Jacksonville Jaguars (6-4) are fighting to hold on to slim play-off hopes. So are the team they meet today, the San Francisco 49ers (4-6). The Jaguars have won three in a row by eight points. The 49ers have lost four of their last five. Something has to give.

The Kansas City Chiefs (3-7) will try to win their third in a row for the first time in three years against the San Diego Chargers (7-3), who took the AFC West lead from the Denver Broncos last Sunday. Denver won on Thursday at the New York Giants, so ,to avoid a tie for first place, San Diego must win their sixth successive game. The Chargers will be wary of wide receiver Chris Chambers, who they cut on November 2. Last weekend he caught a 61-yard throw to help the Chiefs beat Pittsburgh and he would love to do the same - or worse - to his former employers.